Is it actually doing the function call? Or does it think this is just
some function reference and not doing the call?

Well, a function name is a pointer. And you can do things with pointers.
But in this case, it seems like it's just evaluating the pointer and doing
nothing with it. The same thing as a statement like:

12;

It compiles, but basically does nothing.

member function pointer are not combined with object pointers to
esablish a pointer to function in C++.there is nothing such as
delegates in standard C++(in MS C# this would have a meaning).So the
question is still on.why should that line generate an error in a
compiler?.

That's almost true for ordinary functions, but not for member functions.
For ordinary funtions, the name of the function decays into a pointer to
the function in most contexts. There is no such rule for member function
names.

And you can do things with pointers.
But in this case, it seems like it's just evaluating the pointer and doing
nothing with it. The same thing as a statement like:

12;

It compiles, but basically does nothing.

That is, in fact, what MS's compilers used to do. But the code is
ill-formed.